Create rubrics that you can store in your own library and use online to check student work. The rubrics provide an option for narrative comments, and the teacher's dashboard allows you to crunch data by student, assignment, or attribute. All for free!
One initial lesson for writer's notebooks is to Read Ralph Fletcher's opening story in Keeping a Writer's Notebook. It's about digging a ditch and catching all kinds of critters. He compares writer's notebooks to that ditch -- a space we dig in our busy lives to catch stuff. After reading the story, my students and I brainstorm the different kinds of things we could catch in our writer's notebooks. Then I typed the chart in a format that made it easy for students to tape it to the inside cover of their notebooks. Here's what we came up with: